Bag and method of producing the same



' Dec. 2l, 1937.

F. T. ROBINSON BAG AND METHOD OF' PRODUCING THE SAME Filed Aug. 19, 1933 4 Sheets-Sheet l Mij/M44 ATTORN EYS INVENTOR Francis T Robi/15cm Dec. 2l, 1937. F. T. ROBINSON BAG AND METHOD 0F PRODUCING THE SAME 4 Sheets-Sheet 2 Filed Aug. 19, 1933 lNvENToR Francisl T Robmson ATTORNEYS Dec. 2l, 1937, F. T. ROBINSON BAG AND METHOD OF PRODUCING 'IUHE SAME 4 Sheets-Shet 3 Filed Aug. 19, 1955 INVENTOR Francis T Robmson MM TORNEYS Dee. 2l, 1937. F. T. ROBINSON kBAG AND METHOD OF PRODUCING THE SAME Filed Aug. 19, 1935 4 Sheets-Sheet 4 INVENTOR v Francis T Robmson MMV/M, ATTORNEYS Patented Dec. 21, 1937 UNITED ASTATES PATENT oFFlcE Francis T. Robinson, Rockville Centre, N. Y., as-

signor to Arkell Safety Bag Company, New York, N. Y., a corporation of New/.York

Application August 19, 193s, serial No. ssasos 8 Claims.

Bags for certain chemicals and other products that must be protected from air and moisture are commonly made from paper-lined fabric, the lining being secured to the fabric envelope by means of a waterproof adhesive such as asphalt. The paper lining is usually crinkled to provide the necessary pliabllity, and the fabric envelope is usually of burlap or other coarsely woven material. In making the bag, a sheet of this paperlined fabric is folded over upon itself and then the longitudinal edges and the edges at one end of the folded blank are turned over and secured by means of a line of stitches to form the bag seams. It has been found, however, that in the use of bags of this type leakage of air and moisture through the needle holes at the seams is likely to occur which, of course, is objectionable.

One of the'objects of the present invention is to provide a sewed `seam for bags which is effectively sealed against the admission of air and moisture and which is of simple and strong construction. Another of the objects of my invention is to provide a novel and improved method for forming the seams. While my improved seam is particularly adapted for paper-lined fabric bags of the character indicated, it is also adapted for use for other bags where it is desired to obtain a moisture proof and tight seam of strong construction.

'I'he several ,features of the invention, whereby the above-mentioned and other objects may be attained, will be readily understood from the following description and accompanying drawings, in which:

Figure 1 is a view in perspective of a paperlined fabric bag embodying the features of my invention in their preferredA form;

Fig. 2 is a sectional view, on an enlarged. scale, taken onthe line 2-2 of Fig. 1;

Fig. 3 is a similar view but with the bag partially opened adjacent the seam;

Fig. 4 is a view corresponding to the lower.

portion of Fig. 1 of a crinkledpaper bag having its lower end closed by my improved seam;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 4;

Fig. 6 is a plan view of a blank i the course of manufacture of my improved b the 'view illustrating one of the initial steps of my improved method;

Fig. '7 is a view in perspective of-a portion of the blank illustrating another step in the formation of the -end seam of the bag;

Fig. 8 is a view in perspective of the blank edge of said side of the lined fabric.

(c1. os-35) illustrating an initial step in the formation of the longitudinal edge or side seam;

Fig. 9 is a view in perspective of a calking strip that may be employed in forming the seam;

Fig. 10 is a view similar to Fig. 8 illustrating a subsequent step in the formation of the side seam;

Fig. 11 is a View in perspective of another step in the formation of the side seam;

Fig. 12 is a similar 'View of a blank with the side seam completed;

Fig. 13 is a similar view with both the side and end seams completed Fig. 14 is a view in perspective of a bag tube for use in forming a, bag such as a multi-ply paper bag that is particularly adapted for cement;

' Figs. 15, 16, and 1'7A are views in perspective illustrating successive steps in forming the seam for closing the bag tube 'illustrated in Fig. 14; f

Figs. 18 and 19 are sectional views on an enlarged scale respectively taken on the lines I8-l8 and I 9--I9 of Fig. 17;

Fig. 20 is a view similar to Fig. 13 of a modified construction.

'I'he bag illustrated in Fig. 1 of the drawings is made from a sheet of paper-lined fabric comprising an outer envelope 2v of burlap or other coarsely woven material, and a lining 4 of paper which may be crinkled or otherwise treated to provide for the necessary pliability, the paper lining being secured to the fabric envelope by asphalt or other waterproofing adhesive.

In forming this bag, a sheet of the paper-lined fabric is centrally folded over upon itself so as to position its longitudinal edges 6 and the edges 8' at one end thereof together (Figs. 6 and 7). In accordance with my improved method as illustrated in the drawings, previously to folding the lined fabric, a strip l0 of paper"(lig. 9) folded on its longitudinal center line is secured by adhesive I2 across one end of the paper lining at one side of the center line thereof. The strip extends a slight distance beyond the center line of the lining and the adjacent edges of the strip are spaced a distance inwardly from` the lend When the lined fabric is then folded upon itself, the other side of the paper lining is secured by the adhesive |2 to the folded strip. 'Ihe adhesive I2 may be applied initially either to the strip I0 as shown or to the lining.

The adhesive I2 may be applied in two spaced bars or. stripes adjacent the longitudinal edges of the strip as shown so that when thefabric is portion er the uned fabric es described, the

margins at the longitudinal edges of the strip may be turned outwardly into a substantially horizontal position as shown in Fig. 8. This op` eration 'causes the endl I8 of the folded strip in to openl and to fold back over the outwardly turned longitudinal margins of the material in a substantially V-form as shown, the adhesive being still moist, allowing the necessary stripping of the outer end of the strip. from the material. A second strip I is then applied over the outturned longitudinal margins of the lining, the

longitudinal edges of the strip being spaced a.'

distance inwardly from the longitudinal edges of said margins. The margins may be then brought together as shown in Fig. 11, causing the strip to be longitudinally folded uponitself between them. The outer edge portions of the two walls of the material are turned over upon the side of the material to form a fold i8, the line of fold being adjacent the longitudinal edges of the folded strip. This fold I8 is then secured by means of a line of stitches 20 which may be centrally located with respect to the longitudinal edges of the fold and which extends through the adheslvely secured portions of the strip, the line of stitches being spaced a distance from. the unsecured central portion of the strip. The end edge p0rtion 22 is then folded over on a line arranged adjacent the longitudinal edges of the strip l0. This fold 22 is then securedv by aline of stitches 24 which extends through the adhesively secured portions of the strip l0 and is spaced a distance from the unsecured central portion I4 of the strip.

' The unsecured portions Il of the strips It) are preferably of sufficient width so that no material strain is placed on them that would tend to rip the'secured lportions of the strips from the material when the bag is filled. The strips I0 serve as calking strips for the seams to prevent the entrance of air and moisture through the needle holes in the seam. The calking strips l0 may be crinkled to make them pliable and may be treated with suitable moisture-proof material and, also, the adhesive employed may be,

waterproof so that moisture is effectively prevented from either passing through the material of the strip or affecting the adhesive. The slack unsecured portion i4 of the calking strip serves to cushion the strain placed by .the contents of the bag on the seam, and owing to the increased thickness provided by the stitches passing through the sides of the calking strip, the seam is otherwise materially strengthened.

In paper bags where no fabric is employed it is frequently desired to make them moisture, air and sift proof and it will be apparent that my improved seam may be used in such bags as illustrated in Figs. 4 and 5.

In Figs. 14 to 19 there is illustrated a method 'of forming my improved seam in closing the ends of a bag tube such as a multi-ply bag tube that is commonly used for cement and other weighty material. In forming the seams of this bag tube, the longitudinal sides may be folded inwardly to provide bellows folds `26. Afterthe forming of these folds to close the upper end of the bag tube, the upper right hand corner is tucked downwardly to form a V-fold 28, and the left hand upper corner is provided with a deeper tuck or fold 29 to form a valve in the completed bag.

When the tucks 2i and 2l are formed. the edge portions of the upper end of the bag are turned outwardly as shown in Fig. 16 andl a strip l0 issecured over the outwardly turned portions. 'I'his strip Il has its central portion left unsecured but is secured by adhesive to both the inner sides of the outer sides of the outwardly turned portions. The outwardly turned portions with the strip between them are then brought together and secured by a line of stitches I2 which extends through the adhesively secured portions of the strip and spaced a distance outwardly from the central unsecured portion of the strip. This completes the formation of the seam for the upper end of the bag tube. It will be apparent that the lower end of the tube may be similarly \closed by my improved seam. Y

The strip l0 as thus applied serves as a calking strip for the seam, the same `as the strip I0 for the paper-lined fabric bag as above described. Also, as the stitches pass through the several folds of the strip these folds add to the strength of the seam. In some instances, the unsecured central portion of the strip may be of sufficient width so that in opening up the seam there will be no tendency to rip the strip from the sides of the walls of the bag. If desired, however, by `using strong adhesive, the unsecured central portion of the strip may be of sufiiciently narrow width so that in opening up the bag the unsecured portion of the strip will take a part of the strain on the stitches and thus serve to reinforce the seam. L

In some cases the seam may still further be reinforced by a strip 34 folded over the seam (Fig. This strip may be secured by adhesive to th'e two sides and edges of the walls of the bag. In this case the folds of the strip 30 may be omittedfrom the outer Sides of the walls as shown to save material. y

As will be evident to those skilled in the art, my invention permits various other modifications without departing from the spirit thereof orthe scope of the appended claims.

-What I claim is:

1. The method of forming a seam for bags of the class described which ycomprises turning outwardly opposed marginal portions of the walls of the bag, securing a strip by means of adhesive over said outwardly turned portions with the longitudinal central portion of the strip left unsecured, bringing said outwardly turned portions together with the strip folded over upon itself between them, folding over the longitudinal v edge portions of the two walls against a side ofA the bag, and stitching the seam by means gf a line of stitches extending through said folded edge portions and said strip, the line of stitches being spaced a distance outwardly from the edges of said unsecured central portion of the strip.

2. 'I'he method of forming a seamv for bags of the class described, which comprises turning outwardly opposed marginal portions of the walls of the bag, securing a strip by means of adhesive over said outwardly turned portions with the longitudinal central portion of the strip left unsecured, bringing said outwardlv turned portions together with the strip folded over upon itself between them, and stitching the seam by means of a line of stitches extending through said op posed marginal portions, the line of stitches being spaced a distance outwardly from the edges of said unsecured central portion of the strip.

3. The method of forming a seam for bags of the class described, which comprises securing a strip by means of adhesive over the inner sides of' opposed marginal portions of the walls of the bag with the central portion of the strip left unsecured, folding projecting longitudinal edge portions of the strip over the outer sides of said marginal portions, and stitching the seam by means of a line of stitches spaced a distance from the unsecured central portion of the strip, the line of stitches being so spaced that the adhesive extends beyond it.

4. The method of forming a bag of the class described which comprises folding material oi which the bag is to be made upon itself so as to position its longitudinal edges and its end edges together, securing a strip to the inner sides of the margins of one end of the bag blank with the longitudinal central portion of the strip left unsecured, turning outwardly the longitudinal edge portions of the material, securing by-means of adhesive a strip to the inner sides of said outwardly turned marginal portions and to the end of the first mentioned strip, positioning said marginal portions together, folding over the 1ongitudinal edges of the material against the side of the bag,- and securing the seam by means of a line of stitches extending through said folded over edge portions and spaced a distance outwardly from the central unsecured portion of the associated strip. folding over the edges of said end of the partially completed bag, and stitching the seam by means of a line of stitches extending through said folded over edges and spaced a distance outwardly from the edges of said unsecured central portion of the strip.

5. A bag having its edges closed by a seam comprising a strip folded longitudinally upon itself and secured by adhesive to the inner sides of the walls of the bag, with its longitudinal edges spaced inwardly from the edges ofthe bag and A with theV central portion of the strip innermost and left unsecured. said edges of the bag being folded over against the-side of the bag, and a line of stitches extending through said secured edges andthrough the folded portions of the strip, said line of .stitches being spaced outwardly from said unsecured portion of the strip.

6. A bag having the opposed edges thereof .closed 4by a seam, comprising a strip folded 1ongitudinally upon itself between the walls of the bag and folded over the edges of said walls, the outer portions of 'said folds of the strip between the walls being respectively secured by adhesive to the inner sides of said walls, the inner portion of said strip being unsecured, and a. line of stitches extending through said walls and said folds of the strip and spaced a distance outwardly from said unsecured portion of the strip.

7. The method of forming a seam for bags of the class described which comprises securing longitudinal edge portions of a strip spaced inwardly from the edges o f the bag tothe inner sides of the marginalportions of the bag by means of adhesive, the central portion of the strip being unsecured, folding over said projecting portions of the walls of the bag against one side of the bag and stitching the same by means of a line of stitches extending through said folded over portions of the walls of the bag and said secured portions of said strip.

8. A bag comprising two pieces of material secured together by means of seams comprising a strip longitudinally folded over upon itself and secured by adhesive to the inner side of the material with the central portion of the strip innermost and unsecured, a second strip arranged at right angles tosaid ilrst strip and similarly secured, said first strip forming a fold to interlock said second strip and close the corner.

FRANCIS T. ROBINSON. 

